Chapter 6, Section 1-CI, Exercise 015

What sample size is needed to give a margin of error within

7%

in estimating a population proportion with99%

confidence?

a. Usez

-values rounded to three decimal places. Round your answer up to the nearest integer.

Sample size=

Chapter 6, Section 1-CI, Exercise 027

Democrat or Republican? 2015

In 2015, a survey of12,000

American adults found that29.0

%

identified as Democrats and26.0

%

identified as Republicans, with the rest identifying as independent or other.¹

If we want90%

confidence, what are the margins of error in the estimate for the proportion of Democrats and for the proportion of Republicans?

Round your answers to four decimal places.

a. PartyMargin of ErrorDemocrats:

b. Republicans:

Chapter 6, Section 1-CI, Exercise 033

Comparing Normal and Bootstrap Confidence Intervals

Find a95

%

confidence interval for the proportion two ways, usingStatKeyor other technology and percentiles from a bootstrap distribution and using the normal distribution and the formula for standard error.

Proportion of Reese's Pieces that are orange, usingp

^

=

0.48

withn

=

150

Clickhereto accessStatKey.

Round your answers to two decimal places.

MethodConfidence intervalBootstrap:

to

Normal:

to